RRDTUNE(1)                           rrdtool                          RRDTUNE(1)

NAME
     rrdtune - Modify some basic properties of a Round Robin Database

SYNOPSIS
     rrdtool    tune    filename   [--heartbeat|-h ds-name:heartbeat]   [--mini‐
     mum|-i ds-name:min]                              [--maximum|-a ds-name:max]
     [--data-source-type|-d ds-name:DST]                      [--data-source-re‐
     name|-r old-name:new-name]                      [--deltapos|-p scale-value]
     [--deltaneg|-n scale-value]      [--failure-threshold|-f failure-threshold]
     [--window-length|-w window-length]          [--alpha|-x adaption-parameter]
     [--beta|-y adaption-parameter] [--gamma|-z adaption-parameter] [--gamma-de‐
     viation|-v adaption-parameter]   [--smoothing-window|-s fraction-of-season]
     [--smoothing-window-deviation|-S fraction-of-season]        [--aberrant-re‐
     set|-b ds-name]   [--step|-t newstep]  [--daemon|-D address]  [DEL:ds-name]
     [DS:ds-spec] [DELRRA:index] [RRA:rra-spec] [RRA#index:[+-=]<number]>

DESCRIPTION
     The tune option allows you to alter some of the basic configuration  values
     stored in the header area of a Round Robin Database (RRD).

     One application of the tune function is to relax the validation rules on an
     RRD. This allows you to fill a new RRD with data available in larger inter‐
     vals than what you would normally want to permit. Be very careful with tune
     operations  for COMPUTE data sources.  Setting the min, max, and  heartbeat
     for a COMPUTE data source without  changing  the  data  source  type  to  a
     non-COMPUTE DST WILL corrupt the data source header in the RRD.

     A  second  application  of  the tune function is to set or alter parameters
     used by the specialized function RRAs for aberrant behavior detection.

     Still another application is to add or remove data sources (DS)  or  add  /
     remove  or  alter  some aspects of round-robin archives (RRA). These opera‐
     tions are not really done in-place, but rather generate a new RRD file  in‐
     ternally  and  move  it  over the original file. Data is kept intact during
     these operations.  For even more in-depth modifications you may review  the
     --source  and  --template options of the create function which allow you to
     combine multiple RRD files into a new one and which is even more clever  in
     what data it is able to keep or "regenerate".

     filenameThe name of the RRD you want to tune.

     --heartbeat|-h ds-name:heartbeat
             modify  the  heartbeat  of a data source. By setting this to a high
             value the RRD will accept things like one value per day.

     --minimum|-i ds-name:min
             alter the minimum value acceptable as input from the  data  source.
             Setting min to 'U' will disable this limit.

     --maximum|-a ds-name:max
             alter  the  maximum value acceptable as input from the data source.
             Setting max to 'U' will disable this limit.

     --data-source-type|-d ds-name:DST
             alter the type DST of a data source.

     --data-source-rename|-r old-name:new-name
             rename a data source.

     --deltapos|-p scale-value
             Alter the deviation scaling factor for the upper bound of the  con‐
             fidence  band used internally to calculate violations for the FAIL‐
             URES RRA. The default value is 2. Note that this parameter  is  not
             related  to graphing confidence bounds which must be specified as a
             CDEF argument to generate a graph with confidence bounds. The graph
             scale factor need not to agree with the value  used  internally  by
             the FAILURES RRA.

     --deltaneg|-n scale-value
             Alter  the deviation scaling factor for the lower bound of the con‐
             fidence band used internally to calculate violations for the  FAIL‐
             URES RRA. The default value is 2. As with --deltapos, this argument
             is  unrelated  to  the scale factor chosen when graphing confidence
             bounds.

     --failure-threshold|-f failure-threshold
             Alter the number of confidence bound violations that  constitute  a
             failure  for  purposes of the FAILURES RRA. This must be an integer
             less than or equal to the window length of the FAILURES  RRA.  This
             restriction  is  not  verified by the tune option, so one can reset
             failure-threshold and window-length  simultaneously.  Setting  this
             option will reset the count of violations to 0.

     --window-length|-w window-length
             Alter  the  number of time points in the temporal window for deter‐
             mining failures. This must be an integer greater than or  equal  to
             the window length of the FAILURES RRA and less than or equal to 28.
             Setting this option will reset the count of violations to 0.

     --alpha|-x adaption-parameter
             Alter the intercept adaptation parameter for the Holt-Winters fore‐
             casting algorithm. This parameter must be between 0 and 1.

     --beta|-y adaption-parameter
             Alter the slope adaptation parameter for the Holt-Winters forecast‐
             ing algorithm. This parameter must be between 0 and 1.

     --gamma|-z adaption-parameter
             Alter  the  seasonal  coefficient adaptation parameter for the SEA‐
             SONAL RRA. This parameter must be between 0 and 1.

     --gamma-deviation|-v adaption-parameter
             Alter the seasonal deviation adaptation parameter for  the  DEVSEA‐
             SONAL RRA. This parameter must be between 0 and 1.

     --smoothing-window|-s fraction-of-season
             Alter  the  size of the smoothing window for the SEASONAL RRA. This
             must be between 0 and 1.

     --smoothing-window-deviation|-S fraction-of-season
             Alter the size of the smoothing window  for  the  DEVSEASONAL  RRA.
             This must be between 0 and 1.

     --aberrant-reset|-b ds-name
             This option causes the aberrant behavior detection algorithm to re‐
             set  for  the  specified data source; that is, forget all it is has
             learnt so far.  Specifically, for the HWPREDICT or MHWPREDICT  RRA,
             it  sets  the  intercept and slope coefficients to unknown. For the
             SEASONAL RRA, it sets all seasonal coefficients to unknown. For the
             DEVSEASONAL RRA, it sets all seasonal deviation coefficients to un‐
             known. For the FAILURES RRA, it erases the violation history.  Note
             that  reset  does not erase past predictions (the values of the HW‐
             PREDICT or MHWPREDICT RRA), predicted deviations (the values of the
             DEVPREDICT RRA), or failure history (the  values  of  the  FAILURES
             RRA).   This  option  will function even if not all the listed RRAs
             are present.

             Due to the implementation of this option, there is an indirect  im‐
             pact on other data sources in the RRD. A smoothing algorithm is ap‐
             plied  to SEASONAL and DEVSEASONAL values on a periodic basis. Dur‐
             ing bootstrap initialization this smoothing is deferred. For  effi‐
             ciency,  the  implementation  of  smoothing is not data source spe‐
             cific. This means that utilizing reset for one data source will de‐
             lay running the smoothing algorithm for all  data  sources  in  the
             file.  This  is  unlikely  to have serious consequences, unless the
             data being collected for the non-reset data  sources  is  unusually
             volatile  during  the  reinitialization  period  of  the reset data
             source.

             Use of this tuning option is advised when the behavior of the  data
             source time series changes in a drastic and permanent manner.

     --step|-t newstep
             Changes the step size of the RRD to newstep.

             TODO: add proper documentation

     --daemon|-D address
             NOTE:  Because  the -d (small letter 'd') option was already taken,
             this function (unlike most other) uses the capital letter  'D'  for
             the one-letter option to name the cache daemon.

             If  given,  RRDtool  will try to connect to the caching daemon rrd‐
             cached at address and will fail if the connection cannot be  estab‐
             lished.  If the connection is successfully established the data for
             the filename will be flushed before performing the copy/modify  op‐
             eration.  Afterwards  the  filename  will be forgotten by the cache
             daemon, so that the next access using the caching daemon will  read
             the proper structure.

             This  sequence  of  operations  is designed to achieve a consistent
             overall result with respect to RRD internal file  consistency  when
             using  one  of  the DS or RRA changing operations (that is: the re‐
             sulting file should always be a valid RRD file, regardless of  con‐
             current  updates  through the caching daemon).  Regarding data con‐
             sistency such guarantees are not made:  Without  external  synchro‐
             nization concurrent updates may be lost.

             For  a list of accepted formats, see the -l option in the rrdcached
             manual.

     DEL:ds-name
             Every data source named with a DEL specification will  be  removed.
             The  resulting  RRD  will miss both the definition and the data for
             that data source. Multiple DEL specifications are permitted.

     DS:ds-spec
             For every such data source definition (for the exact syntax see the
             create command), a new data source will be added to the RRD. Multi‐
             ple DS specifications are permitted.

     DELRRA:index
             Removes the RRA with index index. The index is zero-based, that  is
             the very first RRA has index 0.

     RRA:rra-spec
             For  every  such  archive  definition (for the exact syntax see the
             create command), a new RRA will be added to the output RRD.  Multi‐
             ple RRA specifications are permitted.

     RRA#index:[+-=]<number>
             Adds/removes  or sets the given number of rows for the RRA with in‐
             dex <index>. The index is zero-based, that is the  very  first  RRA
             has index 0.

EXAMPLE 1
     "rrdtool tune data.rrd -h in:100000 -h out:100000 -h through:100000"

     Set  the  minimum  required  heartbeat  for  data  sources  'in', 'out' and
     'through' to 100'000 seconds which is a little over one  day  in  data.rrd.
     This  would allow to feed old data from MRTG-2.0 right into RRDtool without
     generating *UNKNOWN* entries.

EXAMPLE 2
     "rrdtool tune monitor.rrd --window-length 5 --failure-threshold 3"

     If the FAILURES RRA is implicitly created, the default window-length  is  9
     and  the default failure-threshold is 7. This command now defines a failure
     as 3 or more violations in a temporal window of 5 time points.

EXAMPLE 3
     "rrdtool tune some.rrd DEL:a RRA#0:+10"

     Delete the data source named a and extend the  very  first  archive  by  10
     rows.   This  will in fact replace the input RRD with a new RRD keeping all
     existing data.  For most practical use cases this is identical  to  a  real
     in-place modification.

AUTHORS
     Tobias Oetiker <tobi@oetiker.ch>, Peter Stamfest <peter@stamfest.at>

1.11.0                             2026-08-08                         RRDTUNE(1)
